Heavy tanks are large, heavy vehicles which often act as a team's vanguard. They are represented by a three-piece green or red diamond on the mini-map and over their respective target marker.
Heavy tanks are generally the most well armored vehicles in the game and usually have more firepower than light tanks and medium tanks of their tier, though tank destroyers and artillery still have more alpha damage. Their heavy armor and guns come at the cost of poor speed and maneuverability, which leave poorly-positioned heavy tanks prone to flanking by smaller, faster types of vehicles. They are also the hardest vehicles to conceal; heavy tanks have some of the worst camo values in the game and are easily spotted when in the open.
As heavy tanks are the toughest vehicles in the game, it is often their job to take control of or hold the major choke points and routes of attack on a map. When in such positions, heavy tanks can use techniques such as sidescraping and hull-down positioning to maximize their survivability while exploiting enemy heavies' weakspots to do effective damage in return. Heavy tanks are safest in straight, narrow corridors that not only force enemies to attack them head-on, but give them cover from flankers, artillery, and snipers. Because of their dependence on protection from these threats, heavy tanks are most effective early in a game. As a game progresses and heavy tanks are forced to advance into the open (sometimes without flanking support from allies), their poor camo values and maneuverability make them vulnerable to being outmaneuvered, sniped, or ambushed.
Variety and Examples
Heavy tanks vary mostly in how their armor is most effectively used. In order to reliably bounce shots, American heavies must use hull-down positioning, German heavies and most Russian KVs need to be properly angled, while on contrary Russian IS-series heavies have less effective armour thickness when angled, due to their pike-nose shaped hull. Chinese heavies must conceal their lower plate, and Japanese heavies are best at facing their front directly to their opponents due to they have either weak side armor or weak hull cheeks which limits their angling capacities. Though most heavy tanks fit the role of armored brawlers, there are a number of exceptions which trade armor for other strengths. Tanks like the Churchill I and Tiger I have thinner armor than most heavies, but have accurate and "powerful" guns which allow them to fight at a greater distance. Others, like the KV-85 and many French heavies sacrifice armor for greater maneuverability, effectively making them large medium tanks.